The invention relates to a semiconductor device having an interconnection substrate and semiconductor integrated circuits located on the interconnection substrate, and an inspection contactor for inspecting the electrical continuity of a wafer to be inspected.
Hitherto, in order to realize with a low cost a semiconductor device or system LSI with high-degree, complicated functions by use of flip chip bonding in which a plurality of LSI chips are directly mounted on an interconnection substrate, a bump connection system using bumps formed of solder or metal is used as a mounting method for mounting, after independently producing chips each having a function such as micro-computer or memory etc., the produced chips on the interconnection substrate at a high density.
However, in the bump connection system using the bumps formed of the solder or metal, there is such a problem as thermal strain occurs in the bumps etc. due to difference in thermal expansion coefficient between the LSI chips and the interconnection substrate with the result that fatigue fracture occurs in the bumps etc.
As means for preventing this problem from occurring, there is a method in which a gap defined between the LSI chip and the interconnection substrate is filled with an epoxy type thermosetting resin in which fine particles (usually called xe2x80x9cfillerxe2x80x9d) such as glass particles etc. are included, so that thermal warp between the LSI chip and the interconnection substrate may be restrained, whereby thermal stress occurring in the metal bumps etc. are reduced to thereby improve the connection reliability of the metal bumps etc.
Further, a method disclosed in JP-A-10-270496 (a mounting method usually called xe2x80x9cunderfill structurexe2x80x9d) is known in which an anisotropic, conductive resin is used as the epoxy type thermosetting resin in which fine particles such as glass particles etc. are included. Or, as a method of realizing the system LSI, there is known a method comprising the steps of: arranging a plurality of chips, which are individually produced previously, on an identical plane; and then electrically connecting the chips to each other by use of thin film interconnection technique.
However, in the conventional methods explained above, there are such problems as a step of filling with resin is necessary after mounting the LSI chips on the interconnection substrate with the result that a production cost thereof becomes high, and as, in a case where troubles such as defective chip etc. are found in the reliability test etc. after the assembling thereof, the filled resin must be removed to exchange the defective LSI chip with the result that much labor is required.
Further, in a case where LSI chips are mounted at a high density, it becomes indispensable, due to the increase of generated-heat occurrence density of the whole of a device, to provide a heat-dissipating mechanism for improving the heat dissipation of the whole device, which impedes the small size design of the device.
In addition, in a case of using a bonding method other than the above method using the solder bumps, it is necessary to perform with high precision the alignment between a LSI chip and electrode pads located on an interconnection substrate, which has been an obstacle to the simplification of operations for mounting the LSI chip on the substrate.
The object of the invention is to obtain a semiconductor device and an inspection contactor both superior in heat dissipation in each of which a plurality of LSI chips are mounted on an interconnection substrate having substantially no difference in thermal expansion coefficient between the LSI chips and the substrate by use of means distinct from conventional bonding or connecting, whereby the exchange or mounting of the chips can be readily performed.
According to the first aspect of the invention, there is provided a semiconductor device comprising:
an inner cover made of a material containing silicon as the main constituent thereof in which inner cover LSI chips each provided with semiconductor integrated circuits are located;
an interconnection substrate made of a material containing silicon as the main constituent thereof and connected to the inner cover, the substrate being provided on the surface thereof with electrode terminals each formed to have a pyramid-like shape at a portion of a cantilever which electrode terminals are electrically in contact with the LSI chips, an interconnection layer connected to the electrode terminals, and electrodes for performing electrical connection to exterior portions which electrodes are connected to the interconnection layer, and
an outer cover made of a metal other than silicon or a macromolecular material which outer cover covers the inner cover and the interconnection substrate.
Preferably, in the first aspect of the invention, the interconnection substrate and the inner cover are connected to each other through fitting portions.
According to the second aspect of the invention, there is provided a semiconductor device comprising:
a first inner cover made of a material containing silicon as the main constituent thereof in which is located at least one LSI chip provided with semiconductor integrated circuits;
a second inner cover made of a material containing silicon as the main constituent thereof in which is located at least one LSI chip provided with semiconductor integrated circuits;
an interconnection substrate made of a material containing silicon as the main constituent thereof, the substrate being provided on one face thereof with electrode terminals each formed to have a pyramid-like shape in a portion of a cantilever which electrode terminals are in electrical contact with the LSI chip located in the first inner cover, a first interconnection layer connected to the electrode terminals, and electrodes connected to the first interconnection layer which electrodes perform electric connection to exterior portions, the substrate being further provided on the other face thereof with electrode terminals each formed to have a pyramid-like shape in a portion of a cantilever which electrode terminals are in electrical contact with the LSI chip located in the second inner cover, a second interconnection layer connected to the electrode terminals formed on the other face of the substrate, and a third interconnection layer for connecting the first interconnection layer to the second interconnection layer, the one face of the interconnection substrate being connected to the first inner cover, the other face of the interconnection substrate being connected to the second inner cover; and
an outer cover made of a metal different from silicon or a macromolecular material which outer cover covers the first inner cover, the second inner cover and the interconnection substrate.
Preferably, in the second aspect of the invention, the interconnection substrate, the first inner cover and the second inner cover are connected to each other through fitting portions.
According to the third aspect of the invention, there is provided a semiconductor device comprising:
a first inner cover made of a material containing silicon as the main constituent thereof in which is located at least one LSI chip provided with semiconductor integrated circuits;
a second inner cover made of a material containing silicon as the main constituent thereof in which is located at least one LSI chip provided with semiconductor integrated circuits;
a silicon cover with an interconnection substrate, the substrate being provided on one face thereof with electrode pads, electrode terminals each formed to have a pyramid-like shape in a portion of a cantilever which electrode terminals are in electrical contact with the electrode pads, and at least one LSI chip having semiconductor integrated circuits, the substrate being further provided on the other face thereof with electrode terminals each formed to have a pyramid-like shape in a portion of a cantilever which electrode terminals are in electrical contact with the LSI chip located in the second inner cover, an interconnection layer connected to the electrode terminals, another interconnection layer for connecting the electrode pads located on the one face of the substrate to the interconnection layer located on the other face thereof, the other face being connected to the second inner cover;
an interconnection substrate made of a material containing silicon as the main constituent thereof, the substrate being provided on one face thereof with electrode terminals each formed to have a pyramid-like shape in a portion of a cantilever which electrode terminals are in electrical contact with the LSI chip located in the first inner cover, a first interconnection layer connected to the electrode terminals, and electrodes connected to the first interconnection layer which electrodes perform electric connection to exterior portions, the substrate being further provided on the other face thereof with electrode terminals each formed to have a pyramid-like shape in a portion of a cantilever which electrode terminals are in electrical contact with the LSI chip located in the silicon cover, a second interconnection layer connected to the electrode terminals formed on the other face of the substrate which second interconnection layer is also connected to the electrode terminals formed on the one face of the silicon cover, and a third interconnection layer for connecting the first interconnection layer to the second interconnection layer, the one face of the interconnection substrate being connected to the first inner cover, the other face of the interconnection substrate being connected to the silicon cover having the interconnection layer; and
an outer cover made of a metal different from silicon or a macromolecular material which outer cover covers the first inner cover, the second inner cover and the interconnection substrate.
Preferably, in the third aspect of the invention, each of the pairs of the interconnection substrate and the first inner cover; the interconnection substrate and the silicon cover having the interconnection layer; and the silicon cover and the second inner cover is connected to each other through fitting portions.
In each of the first to third aspects of the invention, it is preferred that electric parts such as capacitors and/or resistors and/or transistors are mounted in the first inner cover. In addition, in each of the first to third aspect of the invention and the preferred aspects, it is preferred that the first inner cover is provided with concave portions each formed to receive at least the LSI chip, and that at the bottom of each of the concave portions is provided a height variation-reducing layer having high thermal conductivity and superior flexibility.
According to the fourth aspect of the invention, there is provided an inspection contactor for performing the inspection of electrical continuity of a wafer to be inspected, by forcing probes onto a predetermined location of this wafer through a pushing substrate, the inspection contactor comprising:
a first silicon substrate (, i.e., a silicon cover 38) having the probes (, i.e., electrode terminals) formed on a main face of the first silicon substrate;
a second silicon substrate (, i.e., LSI chip 37) provided on the other face opposite to the main face of the first silicon substrate;
a semiconductor circuit: having a plurality of electrode pads formed on the second silicon substrate;
a third silicon substrate (, i.e., interconnection substrate 6a) provided at a side of the second silicon substrate which side is opposed to the first silicon substrate; and
a plurality of external terminals formed on the face of the third silicon substrate which face is opposed to the second silicon substrate,
the number of the external terminals being smaller than the number of the probes,
each of the electrode pads formed in the semiconductor circuit being electrically connected to the probes or the external terminals.
In the fourth aspect of the invention, it is preferred that a concave portion is formed in a face opposite to the main face of the first substrate, and that, in the concave portion, the second silicon substrate is positioned.
Further, in the fourth aspect of the invention, it is preferred that the first silicon substrate or the third silicon substrate is provided with electrode terminals each formed to have a pyramid-like shape at a portion of a cantilever, and that electrode pads formed in the semiconductor circuit are electrically connected to the probes or to the external terminals by means of the electrode terminals.
Preferably, in the fourth aspect of the invention, the semiconductor circuit is a multiplex circuit.
The contactor of the invention comprises the inner cover in which the LSI chips are mounted, the electrode terminals each formed to have a pyramid-like shape at a portion of a cantilever, an interconnection layer electrically connecting the electrode terminals, and electrode pads and another interconnection layer both for performing external electrical connection.
The LSI chips are electrically mounted directly by the contacting thereof through the electrode terminals, without using any bumps used in the conventional bonding or connecting. The cantilever structure is adopted for readily bringing about compressive force at the contacting portions between the electrode terminals and the chip, whereby the electrical connection can be stabilized. In this case, since the compressive force is regulated by the structure of the lever and the amount of the deflection thereof, it is possible to prevent excessive force from being applied to the contacting portions. By use of this connecting method, the exchanging of the chip etc. can be readily performed. Further, since the interconnection substrate is made of silicon, the difference in thermal expansion coefficient between the substrate and the LSI chip becomes very small, so that reinforcing resin used in conventional technique becomes unnecessary, and it is effective to reduce the production cost.
Further, the LSI chips are covered by the inner cover made of the material containing silicon as the main constituent thereof, and both of the interconnection substrate and the inner cover of silicon are connected to each other through the fitting portions. In the cover, the concave portions for positioning the LSI chips are formed previously. As regards all of these concave portions and the cantilever etc. provided on the interconnection substrate, it is possible to perform micro-working by conventional LSI-producing technique or micro-machining technique.
In addition, by using the connecting structure in which the cover and the interconnection substrate are connected to each other by the fitting of them, the positioning between the cover and the interconnection substrate can be performed readily. Thus, by the steps of inserting the LSI chips into the cover and overlapping the interconnection substrate with the cover by the fitting, the positioning of the LSI chips and the interconnection substrate and the mounting of the LSI chips can be performed readily. In this case, by use of the cover formed of silicon, the heat occurring in the LSI chips can be readily dissipated, so that the heat dissipation characteristic of the whole of the semiconductor device is enhanced.
Further, by adopting such structure as the whole structure covered by the inner cover is further covered by the outer cover made of a metal other than silicon or macromolecular material which outer cover is provided with external electrode terminals, it becomes easy to perform the handling thereof and to enhance the mechanical reliability thereof.